The present invention relates to a position measuring device.
A position measuring device of this type is known, e.g., from DE 20 22 151 A1. That publication describes an optical position-measuring device, with which a dimensional standard in the form of a transparent glass scale with periodically located, intransparent position markings is scanned by a scanning unit that includes a lamp and photoelements. The scanning unit generates two phase-shifted, periodic signals that are substantially sinusoidal or cosinusoidal. Furthermore, a monitoring device is provided, which monitors the phase position and amplitude of the phase-shifted, periodic signals. If there is a deviation from a specified target value, the monitoring device outputs an error signal via a separate error output.